Mirror & Water Image — Study Notes

Overview

Mirror and water image questions test a candidate's spatial reasoning and visualization ability. In UP Police Constable exam, you'll see 3–5 questions where you must identify how letters, numbers, words or figures appear when reflected in a mirror (vertical axis) or water (horizontal axis). This is a high-scoring topic because the logic is formulaic — once you grasp the reflection rules, accuracy becomes near-perfect with minimal time investment.

The core skill: mentally "flipping" an object along an axis. Mirror images flip left-right (vertical axis reflection), while water images flip top-bottom (horizontal axis reflection). Questions present an original figure and ask you to pick the correct reflected image from four options. Mastery requires recognizing symmetrical vs asymmetrical letters, understanding axis orientation, and practicing pattern recognition to avoid the common trap of confusing mirror with water reflections.

Expect direct application — no complex reasoning chains. Speed matters: aim to solve each question in 20–30 seconds. This topic often appears alongside paper folding and embedded figures in the Mental Aptitude section.

Key Concepts

• **Mirror Image**: Reflection along a vertical axis placed to the left or right of the object. Left becomes right, right becomes left; top and bottom remain unchanged. Imagine holding text up to a mirror — that's your mirror image.

• **Water Image**: Reflection along a horizontal axis placed below the object. Top becomes bottom, bottom becomes top; left and right positions remain unchanged. Visualize text reflected in still water.

• **Vertical Symmetry**: Letters like A, H, I, M, O, T, U, V, W, X, Y have vertical symmetry — their mirror images look identical to the original. Always check for symmetry first to eliminate options quickly.

• **Horizontal Symmetry**: Letters like B, C, D, E, H, I, K, O, X have horizontal symmetry — their water images may look similar or identical. Fewer letters are horizontally symmetrical than vertically symmetrical.

• **Asymmetric Characters**: Letters like F, G, J, L, N, P, Q, R, S, Z change appearance significantly in both mirror and water images. These are high-yield for elimination in multiple-choice questions.

• **Compound Objects**: When a figure contains multiple elements (clock face, geometric shapes with text), apply reflection rules to each component independently, then combine. The spatial relationship between elements also reverses.

• **Axis Placement**: Mirror axis is typically vertical (left/right of object); water axis is horizontal (below object). Some questions specify axis position — always confirm before answering.

• **Direction Reversal**: In mirror images, arrows pointing left point right and vice versa. In water images, upward arrows point down. Clock hands' positions also reverse in mirror (3 o'clock becomes 9 o'clock).

Formulas / Key Facts

1. **Mirror Image Rule**: For vertical axis reflection, reverse the horizontal sequence. If original is "POLICE", mirror reads as if written right-to-left with each letter also flipped.

2. **Water Image Rule**: For horizontal axis reflection, flip the vertical orientation. Top half moves to bottom, bottom to top, maintaining left-right order.

3. **Symmetrical Letters (Vertical)**: A, H, I, M, O, T, U, V, W, X, Y — mirror images identical to original.

4. **Symmetrical Letters (Horizontal)**: B, C, D, E, H, I, K, O, X — water images similar or identical.

5. **Numbers in Mirror**: 0 and 8 are symmetrical; 3 becomes reversed; 2 and 5 become mirror flips of each other.

6. **Clock Mirror Rule**: Time on mirror image = 12:00 minus actual time. If clock shows 3:15, mirror shows 8:45.

7. **Combined Reflections**: Applying both mirror AND water image returns the original figure rotated 180 degrees.

8. **Letter-by-letter approach**: For words, mentally flip each letter individually, then arrange in reversed order for mirror (same order for water).

Worked Examples

**Example 1: Mirror Image of a Word**

**Question**: Find the mirror image of "CONSTABLE".

**Solution**:

• Step 1: Reverse the letter sequence: ELBATSNOC
• Step 2: Flip each letter horizontally (imagine each facing opposite direction)
• Step 3: Letters like C, E, L, B, T, A, S, N, O change shape when mirrored
• Looking at options, the correct mirror image shows: Reversed sequence with each letter flipped as if seen in a mirror placed to the right
• **Answer**: The option showing Ǝ⅃BAT⅃ИOƆ (stylized representation; actual appearance depends on font)

**Example 2: Water Image of a Number**

**Question**: What is the water image of "2024"?

**Solution**:

• Step 1: Keep horizontal sequence same: 2024
• Step 2: Flip each digit vertically (top becomes bottom)
• Step 3: 2 flipped vertically looks like 2 upside-down; 0 remains 0; 4 flipped looks like 4 upside-down
• The digits appear inverted but in same left-right order
• **Answer**: The option showing each digit flipped along horizontal axis (imagine rotating each 180° individually, not the whole number)

**Example 3: Clock Mirror Image**

**Question**: A clock shows 7:20. What time does its mirror image show?

**Solution**:

• Step 1: Apply clock mirror formula: 12:00 − 7:20
• Step 2: Calculate: 12:00 − 7:20 = 4:40
• Step 3: Verify: Hour hand between 4 and 5, minute hand at 8 (40 minutes)
• **Answer**: 4:40

Common Mistakes

1. **Confusing mirror with water image**: Students apply vertical flip when horizontal is needed or vice versa. **Fix**: Always identify the axis first — vertical line = mirror, horizontal line = water. Draw a small axis marker if needed.

2. **Forgetting to reverse letter sequence in mirror**: Students flip individual letters but keep the same order. **Fix**: Mirror images require BOTH sequence reversal AND individual letter flipping. "UP" in mirror is not "ᴜꟼ" but "ꟼᴜ" (reversed position plus flipped shape).

3. **Assuming symmetrical letters need no change**: Even symmetrical letters must be checked in context. **Fix**: A may be symmetrical, but if it's part of a word, its position in the sequence still changes in mirror image.

4. **Misapplying clock formula**: Students subtract wrongly or confuse AM/PM. **Fix**: Always use 12-hour format. For times after 12, convert to 12-hour first. Double-check minute hand position on clock face.

5. **Not practicing asymmetric letters enough**: Candidates struggle with F, G, J, L, N, P, Q, R, S, Z because these look very different when flipped. **Fix**: Make flashcards of these letters in both mirror and water orientations. Practice writing them reversed until recognition becomes instant.

Quick Reference

• **Mirror = Vertical Flip**: Left↔Right swap; top/bottom unchanged; sequence reverses
• **Water = Horizontal Flip**: Top↔Bottom swap; left/right unchanged; sequence same
• **Symmetry shortcut**: A, H, I, M, O, T, U, V, W, X, Y identical in mirror; check options first
• **Clock mirror formula**: Mirror time = 12:00 − Original time
• **Elimination strategy**: Reject options with wrong axis reflection immediately; cuts choices by 50%
• **Practice drill**: Draw vertical/horizontal lines on paper; practice flipping random words/numbers across each axis daily for 10 minutes until visualization becomes automatic